marsh



(No Model.)

J. W. MARSH. ELEOTRIG CONDUCTOR.

Patented Dec. 29, 1891.

WITNESSES:

UNITED STATES PATENT. OFFICE.

JOSEPH \V. MARSH, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE STANDARDUNDERGROUND CABLE COMPANY, OF SAME PLACE.

ELECTRIC CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 466,250, dated December29, 1891.

Application filed September 30, 1891. Serial No. 407,228- (No model.)

T 00% whom it may concern:

Be it known that I, .TosEPH W. MARSH, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered certain new and usefulImprovements in Electric Conductors, of which improvements the followingis a specification.

The invention described herein relates to certain improvements inelectric cables, and has for its object the arrangement of the wires formetallic circuits in such relation to each other as to obtain themaximum efficiency, and it is further an object to provide for the moreefficient insulation of the wires of a circuit from each other and alsofrom the wires of adjoining circuits, all as more fully hereinafterparticularly described and claimed.

In the accompanying drawings, forming a part of this specification,Figure 1 is a perspective view showingthe manner of arranging the wiresin pairs for a metallic circuit. Figs. 2, 3, 4, and 5 are end views ofdifierent forms of hollow or air-retaining cores for the circuits, andFig. 6 is an end view of a cable having my improved form of conductorsarranged therein.

In the practice of my invention I provide a frame 1, having groovesalong opposite sides thereof, in which I place the bare conducting-wires2, which are bound in place by one or more perforated strips 3 of paperor other fibrous material. As shown in Fig. 1, the frame 1, preferablyof stiff paper or other suitable material, is made hollow, therebyforming a comparatively large air-space between the two wires orconductors employed in a metallic circuit. The perforations in thestrips 3, binding the wires in their grooves, form pockets of airbetween the adjacent wires of two adjoining circuits, as will be readilyunderstood by reference to Fig. 6.

The walls of the frame shown in Fig. 1 are made continuous or integral,while in Figs. 2 and 3 the frame is formed by properly folding a stripof sufficient width into the desired form. Ordinarily the frame 1 wouldbe sufficiently rigid to withstand usual treatment; but when the frame 1is made of light material it may be re-enforced by a tube or shell 4,arranged inside of the frame, as shown in Fig. 3.

In Figs. 4 and 5 the frame consists of the curved walls 5, supportingthe wires, and a single connecting-web 6, the latter being curvedlongitudinally in Fig. 4, so as to hold the walls 5 in proper relationto each other, while in Fig. 5 a strengthening or re-enforcing tube orshell 4 is placed between the walls 5 to hold them in proper relation toeach other. A

It will be observed by reference to Fig. 6 that the wires of a circuitare separated from each other a considerable distance, and that the mostefficient of insulation-2'. e., airis inclosed between, and also thatthe air inclosed in the pockets formed by the perforations in thebinding-strip efficientlyinsulates each wire of a circuit from the wiresof adjoining circuits.

When the paired wires are arranged in a cable, as shown in Fig. 6, it ispreferred to cover them with an imperforate cover 7, consisting of abraid or plain tape, as shown in Fig. 1, if the cable is to be filledwith a sealing material, as paraffine or other suitable insulatingmaterial; but when an unfilled or dry cable is desired the imperforatecovering may be omitted;

I claim herein as my invention 1. The combination of an open frameformed of non-conducting material, wires arranged on opposite sides ofthe frame, and a perforated strip of fibrous material surrounding theframe and wires and binding the latter in position on the frame,substantially as set forth.

2. The combination of an open frame formed of non-conducting material, are-enforcing tube or shell arranged with the frame, conducting-wiresarranged on opposite sides of the frame, and a perforated stripsurrounding ltihe frame and wires, substantially as set ort 3. Thecombination of an open frame formed an imperforate covering,substantially as set [0 forth.

In testimony whereof I have hereunto set my hand.

JOSEPH V. MARSH.

WILLIAM A. CONNER,

\Vitnesses: i JAMES W. SMITH.

